States regulate small group premium rates, typically by placing limits on the premium variation allowable between groups (rate bands). Insurers price to recover their costs over their entire book of small group business while abiding by state rating rules. Over time, the effect of initial underwriting "wears off" as the cost of a group regresses towards the mean. Recent claim experience—whether better or worse than average—is a strong predictor of future costs in the near term. But the average health status of a particular small employer group tends to regress over time towards that of an average group. The process used to price small group coverage changes when a state enacts small group reform laws.
The UK's National Health Service (NHS) is a publicly funded healthcare system that provides coverage to everyone normally resident in the UK. It is not strictly an insurance system because (a) there are no premiums collected, (b) costs are not charged at the patient level and (c) costs are not pre-paid from a pool. However, it does achieve the main aim of insurance which is to spread financial risk arising from ill-health. The costs of running the NHS (est. £104 billion in 2007-8) are met directly from general taxation. The NHS provides the majority of health care in the UK, including primary care, in-patient care, long-term health care, ophthalmology, and dentistry.
The compulsory insurance can be supplemented by private "complementary" insurance policies that allow for coverage of some of the treatment categories not covered by the basic insurance or to improve the standard of room and service in case of hospitalisation. This can include complementary medicine, routine dental treatment and private ward hospitalisation, which are not covered by the compulsory insurance.
A health maintenance organization (HMO) is a type of managed care organization (MCO) that provides a form of health care coverage that is fulfilled through hospitals, doctors, and other providers with which the HMO has a contract. The Health Maintenance Organization Act of 1973 required employers with 25 or more employees to offer federally certified HMO options. Unlike traditional indemnity insurance, an HMO covers only care rendered by those doctors and other professionals who have agreed to treat patients in accordance with the HMO's guidelines and restrictions in exchange for a steady stream of customers. Benefits are provided through a network of providers. Providers may be employees of the HMO ("staff model"), employees of a provider group that has contracted with the HMO ("group model"), or members of an independent practice association ("IPA model"). HMOs may also use a combination of these approaches ("network model").
In addition to medical expense insurance, "health insurance" may also refer to insurance covering disability or long-term nursing or custodial care needs. Different health insurance provides different levels of financial protection and the scope of coverage can vary widely, with more than 40% of insured individuals reporting that their plans do not adequately meet their needs as of 2007.